Optimizing Emissions Reduction in Ammonia-Ethylene Chemical Clusters: Synergistic Integration of Electrification, Carbon Capture, and Hydrogen

The transition of the chemical industry to net-zero CO₂ emissions presents several significant challenges, due to the presence of carbon as material feedstock, the capital-intensive nature of plants, the interdependence of multiple processes within industrial clusters, and the availability of low-carbon electricity, hydrogen, and CO₂ transport and storage. To obtain an effective plan for reducing emissions, a comprehensive modeling approach that accounts for the dynamics of clusters and their interactions with the broader energy system is needed. In light of the aforementioned considerations, the present study develops and applies a mixed-integer linear programming (MILP) model with a one-year hourly resolution to optimize technology selection and operation in two existing ammonia-ethylene clusters. The findings show that significant emission reduction is possible with close-to-market technologies that bridge electrification, green hydrogen, and carbon capture and storage, yet reaching zero emission is not possible. Moreover, the optimal CO₂ reduction strategies are highly cluster-specific and contingent upon the availability of a critical infrastructure. For instance, emissions can increase by up to 118% in the absence of a CO₂ transport and storage infrastructure, because separated CO₂ from reformer syngas cannot be stored or further utilized. While process integration can improve cost-effective CO₂ mitigation, reducing costs by 9-%11% and emissions by 29%-54%, it also limits operational flexibility. The developed framework offers a valuable tool for identifying cluster designs and robust CO₂ emission reduction strategies.